Treatment of vegetable oils



Patented Jan. 8, 1946 UNITED (STAT-E Y TREA MENT S' PATENT, 2,395,350 1 I or vEoE'rABLnon s Percy L. llulian, M aywood, and Herbert T. Iveson,

Chic Ill-,assignors to The (Hidden Company, Cleveland, Ohio, a corporation of Ohio No te v Application Jul 1 5 1942';

a g l-la] No.45 1,q I.

-- 11 claims. (or. 2604424) The present invention relates to the treatment of vegetable oils, such as soybean oil, particularly fact; the addition ofsmall quantities of water to emulsify the phosphatides in the oil is desirable,

to the production of light-colored; non-break oils.

n is known that when oils, such, assc hean oil, are heated that a dark colored precipitate is formed known as break. This is undesirable and a wet alkali refining is customarily employed to produce a non-break oil. When a batch alkali refining is employed it is necessary that-the reaction mixture be allowed to stand to permit 1 settling of the sludge. In a continuous'process accurate proportionating 'devices must be employed and the times and temperature must be rather accurately controlled. In both processes, of course, soap is formed and since water is present there is alwaysthe problem presented-by emulsiflcation of some-oil with resulting loss of the oil so emulsified. This'alkali refining. while retarding the formation of break" at the temperaturesprdinarily employed in the use of the in the'oiltprior to the alkaline treatment andjin since it can conveniently be removed in the emulsion. I v

The-pH ofthe acid clay should be about 5 to ,3. Above a pHvof 5 there is insufilcient bleaching,

'if any.. and below 3 there is some danger of hydrolysis. In the case 'of the alkaline clay the pH should be greater than 8 and pH values much above 10 are to be avoided. It is not necessary, however, that the alkaline clay as added have a pH above 8, as the desiredjresults may be ob tained by adding dry alkali in addition to the alkaline clay'. Thus in one instance 2% of a s I fullers earth having a pH of 8 was ineffective to oil does not produce an oil of materially, lighter color and it is customary to bleach the alkali refined 011. I

. It is accordingly an object of the present invention to provide an improved process for producing alight-colored non-breakoil.

Another object is to provide a substantially dry process for accomplishing the foregoing.

Other and ancillary objects will appear from the description as it proceeds.

v alkali, even in amount suflicient to produce the- It has been found that the objects of the present invention may be accomplished if the oil,

such as soybean oil, is first treated with an'acid clay, and then after removal of the acid clay the f oilis treated with an alkaline clay at a pH above about 8. It is important thatthis order be observed as the results are not attained if theoil is first treated with an alkalineclay and then with the acid clay. Itis also important that the acid clay be removed before the alkaline clayis added as the results are not attained ifthe acid clay is present when the alkaline clay is added.

Also if phosphatides are present in the oil they are preferably removed after. the acid clay treatment. By having them present during the acid clay treatment step much lighter colored phos-v phatides are produced and their presence at this stage does not seem to interfere with the quality of the oil produced, For best results, however,

the phosphatides should be removed prior to'the treatment with the alkaline clay. It is also desirable to remove as much as possible of any water which is present prior to the alkaline treatment. Some water may, of course, be present produce a non-"break oil, but upon the addition of 0.05% of sodium carbonate based'on the weight of the oil, an amount sufflcient to raise the pH of the'clayto 10.1, a non-break oil was produced. The alkali may be either added to the clay as a mixture or the alkaline clay may be treated with thealkali to bring its pH to the desired value. It is importantfhowever, that the clay be alkaline as 'a'dry mixture of acid clay and when so recovered are found to be much lighter in color than when the acid clay treatment is omitted. In fact, the phosphatides produced by' the present invention are lighter in color than the phosphatides recovered in the ordinary way after a single bleach with hydrogen peroxide, and in many cases are as light or lighter than double bleached phosphatides. 1

The thus clarified oil is then treated with the alkaline clay andagain centrifuged or filtered to remove the alkaline clay together with the socalledflbreak material. Oil so produced is very light in color and is non-break at 600 F,

The following examples are given by way of illustration in'order that those skilled in the art may better practice the invention and they represent preferred modes of carrying out the inven- EXAMPLE I -Miscella obtained from the extraction of soybeans with a hydrocarbon solvent was treated with 1.5% by weight of the oil of a calcined acid clay having a pH of 4.00 and 0.5% by weight of the oil of an acid washed clay having a pH of -4.40 at 220-240" F. for -minutes and filtered. The solvent was then removed, 3% of water added and; the phosphatides emulsified; The

emulsion was then separated from the bulk of the oil by centrifuging, separating oil, and drying the emulsion in vacuum. The oil was then treated with 2% by weight of the oil of an alkaline fuller's'v earth having a pH of8.00 and 0.05% of sodium carbonate by weight of the oil for 10 minutes at 220-240 F. after which the oil was again filtered."

A blank was run and the color of the treated oil and treated phosphatide compared with. the blank. The treated oilwas non-break at600' F. while the blank was a break oil. Table I gives the resultspf the color comparisons, th values given being Lovibond. The percent of moisture in the finished treated'oil was between 0.05 and Table! Color-oi hosphaflge (lolor oioil Material Quality Red Yellow Red Yellow Untreated 2.0 46 5.2 36 Break.

Treated 1.0 4.0 0.7 7 Non-break.

In place of the mixture of acid clays either 01' the clays may be used alone, or other acid clays.

may be used provided their pH is less than 5.

EXAMPLE II Phosphatide free soybean oil having a color of I. '5'-red and 36-yellow was treated at 220-240 F.

Miscella was treated as it came from the extract on towers in the commercial extraction of the oil from soybeans with hexane. A large holding tank was allowed to fill up to about A full with miscella and 12# of a calcined acid clay having a pH of 4.0 and 4# of an acid washed clay having a pH of 4.4 was then added and the tank allowed to fill up with miscella, This required from about 8 to 10 minutes during which time the mixture was agitated. The tank was then allowed to empty until it was about one-half full. The miscella-clay mixture was filtered through a press and sent to a still to be' concentrated. Other batches of calcined acid clay and acid washed clay were then added and the tank allowed to fill up again, the process being repeated. This procedure was necessary in order to take care of the continuous flow of miscella from th extraction towers. The batches oi. clay mentioned above were added every twenty minutes and were calculated to be 1.5% of the calcined acid clay and 0.5% of the acid washed clay on the weight of the oil in the miscella.

fI'he miscella was then concentrated. The last traces oi hexane were removed by the treatment with superheated steam. which also emulsified the phosphatides present-in the oil. The mixture of oil and phosphatideemulsion was then centrifuged to remove the emulsion. The'resulting oil was centrifugeda second time to-remove excess moisture and heated to 220 to 240 F. 2% of an alkaline fullers' earth having a pH of 8.0 and-10.05% of sodium carbonate was thenadded and the mixture stirred forten minutes after which it was filtered. The phospha'tide emulsion was dried under vacuum. 4

A simultaneous run was made under the same conditions except that no clay treatments were employed. A comparison between th two oils and the phosphatides produced is hown in Table 11., r

Table H v i Color oiphosphafldes Color oioil 'Material 1 I Quality Red- Yellow Red Yellow Untreated .24: 20 4.3 22 Brook. Treated 1.1 7 0-8 6 Noll-hm.

There have been many complicated procedures proposed for producing non-break oil but it is readily seen that the sequence of steps outlined provides a simple procedure for producing anonbreak oil and at the same time a very light oil is produced. Also a light colored phosphatide is prov duced when starting with phosphatide containing miscella. I I i Having described the invention-what is claimed 1. The process of producing non-break vegetable oil which comprises first treating .the oil with acid clay having a. pH less'than 5. removing the acid clay from the oil, then treating the oil under substantially anhydrous conditions with fullers earth having a pH greater than 8, removing any phosphatides present in the original oil prior to the treatment, with alkaline tullers earth, and finally removing the alkaline fuller's earth from the oil.

2. The process of producing non-break soybean oil which comprises first treating the oil with acid clay having a pH less than 5, removin the acid clay from the oil, then treating the oil under substantially anhydrous conditions with alkaline fullers earth having a pH greater than 8, removing any phosphatides present in the original oil prior to the treatment with alkaline fullers earth, and finally removing the alkalinefullers earth from the oil. I

3. The process of producing nonbreak soybean oil containing phosphatides which comprises treating the oil with acid clay having a pH less .than 5, removing the acid clay from the oil, making an aqueous emulsion of the phosphatides, and separating the aqueous emulsion from the oil,

thereafter treating the oil under substantially anhydrous conditions with alkaline fullcrs earth having a pH greater than 8 and finally removing the alkaline fullers earth from the oil.

4. The process which comprises treating phosphatide-containing vegetable oil miscella with acid clay having apH less than 5. removing the solvent from the miscella, making an aqueous emulsion of the phosphatides, and separating the aqueous emulsion from the oil. recovering the phosphatides from the emulsion, treating the phosphatide-solvent free oil under substantially anhydrous conditions with alkaline fuilers earth havingapliaboveln cnlysiterremovaiofthe acid clay. and separating the alkaline iuller's earth from the oil.

5. The process of claim 4 in which the oil miseella is soybean oil misoella.

6. The process of producing a non-break oil which comprises treating vegetable oil miscella with acid clay having a pH less than 5, removing the solvent from the misoella, removing the acid clay from the oil, then treating the oil under substantially anhydrous conditions with alkaline i'uller's earth having a pH greater than 8.0, removing any phosphatide present in the oil prior to the treatment with alkaline iuller's earth and finally removing the alkaline luliers earth from the oil.

7.Theprocessotclaim6inwhichtheoilis soybean oil.

8. The process oi producing a non-break oil which comprises treating a veeetable oil miscella containing phosphatidea with an atid clay 1mm;

aplileesthanlhremovingtheacidelayiromflw 9. The process of claim 8 in which the oil is soybean oil.

10. The process which comprises treating phosphatide containing vegetable oil miscella with acid clay' having a pH less than 5, removing the solvent irom the miscella, making an aqueous emulsion of the phosphatides, and separating the aqueous emulsion from the oil and recovering the phosphatides from the emulsion.

11. The process of 'ciaim 10 in which the miscella is soybean oil miscella.

L. JUIJAN. HERBERT T. IVESON. 

